Various methods and filling machines for filling containers are known. Among these are methods and filling machines for pressure-filling containers, including large-volume containers. These include plastic or PET containers or kegs with volumes of between 10 and 30 liters.
When one opens a bottle of beer, it is sometimes the case that considerable amounts of beer escape out of the top as a result of foaming. This results from the sudden pressure relief that occurs when one opens the bottle. A known way to avoid this is to open the beer very slowly, by carefully prying off the cap.
A similar difficulty arises in pressure filling a carbonated beverage. During pressure relief, a similar foaming can occur. It is known to reduce or avoid such unwanted foaming by lengthening the pressure-relief phase. However, this reduces the rate at which kegs can be filled and closed.
Large plastic containers are not always made perfectly. To test the containers, it is known to fill them with high-pressure gas to look for leaks. This testing is carried out on empty containers.
Sometimes, a container will burst during this testing. Because of the size of the container and the pressure of the gas, the container in this case is effectively like a small bomb. As a result, there can be considerable damage to machines and installations. Even worse, the extremely loud bang that occurs can lead to hearing damage in those people who are unfortunate enough to be near the container when it bursts.